Method of making shaped articles

ABSTRACT

A method of making a tetrahedral-shaped article from an elongated solid member having equilateral triangular or square cross section in which the elongated polyhedral shape is positioned with two of its edges lying in a plane on one side of the third edge of the triangular cross section. The shape is cut in a plane normal to the first plane through each of the edges and at an angle of 45* to all of the edges. Thereafter the polyhedral shape is rotated so that one of the edges in the plane moves from the plane and the third edge moves into the plane and the cutting process is repeated.

United States Patent METHOD OF MAKING SHAPED ARTICLES 6 Claims, 15 Drawing Figs.

Int. Cl 826d 3/00, B29c i7/i4. 829d 27/06 Field of Search 264/138,

References Cited Primary Examiner- Robert F. White Assistant Examiner.leffery R. Thurlow Attorney-Wolf, Greenfield and Sacks ABSTRACT: A method of making a tetrahedral-shaped article from an elongated solid member having equilateral triangular or square cross section in which the elongated polyhedral shape is positioned with two of its edges lying in a plane on one side of the third edge of the triangular cross section. The shape is cut in a plane normal to the first plane through each of the edges and at an angle of 45to all of the edges. Thereafter the polyhedral shape is rotated so that one of the edges in the plane moves from the plane and the third edge moves into the plane and the cutting process is repeated.

, PATENTED DECMISTI ,SHEET 1 UF 2 slsz'rlase PATENTED nEc-I 4 IQTI SHEEI 2 0F 2 INVENTOR.

1 METHOD OF MAKING SHAPED ARTICLES SUBJECT MATTER OF THE INVENTION The present invention relates to a tetrahedral shaped sponge and a method of making tetrahedral shaped articles such as sponges.

BACKGROUND OF THE INVENTION Common houseware sponges have ordinarily been made in block forms presumably because these forms have been considered easy to make and easy to handle. These block shapes are not universally desirable because there are occasions in which morepractical, working surface would be more useful, for a given volume of material. And while it is possible in many instances to attain greater surface area by merely making the sponge larger this can be accomplished only at the expense of using more material.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved shape for a sponge and in particular to a sponge which has a greater practical, working surface area for a given volume of material.

It is also an object of the present invention to provide an improved sponge having more functional comers with a greater taper than conventional six-sided sponges. A further object of the present invention is to provide an improved sponge having more functional edges and surfaces than conventional sponges. A still further object of this invention is to provide a sponge having a shape which is easy to hold and handle and which nonetheless provides a flat surface for application to a work surface. A still further object of this invention is to provide a sponge with greater body thickness in areas subjected to the most wear. One other object of this invention is to provide a sponge having an attractive, efficient shape that is easy to hold and use.

A further object and advantage of the present invention is to provide an improved method of making tetrahedral shapes from elongated polyhedral shapes which preferably are either rectangular or triangular in cross sectional configuration.

A still further object of the present invention is to provide a means and method of making improved tetrahedral shaped articles in which tetrahedral sanding blocks, pumice blocks, erasers, sponges, rubbing implements and other tetrahedral shapes may be made inexpensively and simply.

A still further object of the present invention is to provide an improved method of making tetrahedral shaped articles in which surfaces of the material from which the tetrahedral shaped articles are formed are so oriented as to enhance the printing or treatment of selected surfaces of the tetrahedral shapes as they are being formed.

In the present invention there is provided a tetrahedral shape that is especially useful as a sponge. The present invention also provides an improved method of making tetrahedral shapes comprising forming an elongated polyhedral shape having a plurality of parallel edges extending lengthwise of the shape. The shape is positioned with two of its edges lying in a first plane and a third edge parallel to an one side of the first plane. The shape is cut in a plane normal to the first plane through each of the edges and at an angle of 45 to all of the edges. The shape is repositioned after it's cut relative to the first plane to place the third edge and one of the first two edges in the plane and with the other of the two edges on one side thereof. Thereafter the polyhedral shape is again out at an angle 90 to the first cut to effect the formation of a plurality of sponges.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the present invention will be more clearly understood when considered in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a tetrahedral shaped sponge embodying the present invention;

FIG. 2 is a top plan view of a segment of an elongated sponge material having a cross section of an equilateral triangle showing an initial step of a preferred method of the present invention;

FIG. 3 is a cross sectional view taken along the line 3-3 of FIG. 2.

FIG. 4 is an end view of the polyhedral shape of FIG. 2 rotated 120 with respect to the orientation illustrated in FIG. 2 for a subsequent step in the method of the present invention;

FIG. 5 is a top plan view of a polyhedral shape as oriented in FIG. 4;

FIG. 6 is an end view of the polyhedral shape of FIG. 5 rotated l20 with respect to the orientation illustrated in FIG.

FIG. 7 is a top plan view of the polyhedral shape as oriented in FIG. 6;

FIG. 8 is an end view of an elongated sponge material having a rectangular cross section showing a first step in a modification of the method of the present invention;

FIG. 9 is a top plan view of the shape as oriented in FIG. 8;

FIG. 10 is an end view of the shape illustrated in FIG. 9 after a step in the process of the present invention looking in the direction of arrows 10-10 of FIG. 9;

FIG. 11 is a top plan view of the shape oriented relative to the orientation illustrated in FIG. 9, after a further step in the invention;

FIG. 12 is an end view of the shape as illustrated in FIG. 11 looking from the direction of arrow 12-12;

FIG. 13 is a subsequent view of the end illustrated in FIG. 12 in a subsequent step of the invention;

FIG. 14 is an end view ofthe shape illustrated in FIG. 13 but rotated 90 relative thereto prior to a subsequent step of the invention, and

FIG. 15 is a top plan view of the polyhedral shape illustrated in FIG. 14.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIGS. 1 through 7 there is illustrated a preferred embodiment of the present invention which illustrates both the structure of an improved sponge and a method of making it. This sponge is formed as a tetrahedral having sides A, B, C and D and is of sufiicient size to be easily handled. Each side in this preferred embodiment is an isosceles triangle with working or functional edges E. Similarly, each of the comers F are functional or working. The sides A, B, C and D are uniform and consequently any one of these sides may be used as a working surface.

The sponge may be formed of a wide variety of compressible resilient materials including, for example foam rubber, cellulose, urethane or other synthetic foam. Cellulose sponges may be made in particularly efficient water absorbent forms while urethane foam sponges may be made to withstand substantial abuse of scrubbing.

The sponge illustrated in FIG. 1 may be formed from polyhedric elongated shapes which are either triangular in cross section as illustrated in FIG. 3 or rectangular in cross section as illustrated in FIG. 8. The method of making the sponges in a tetrahedral shape from the polyhedric shapes of FIGS. 3 and 8, moreover, may be applied to making of other tetrahedral-shaped objects, such as for example, as sanding blocks, pumice blocks, erasers or other rubbing implements.

The process of making tetrahedral shapes from an elongated polyhedric shape having a triangular cross section has certain advantages and disadvantages relative to making tetrahedral shaped objects from elongated polyhedric shapes having rectangular cross sections of the type illustrated in FIG.

In making a tetrahedral object such as the sponge from an elongated shape having a cross section such as illustrated in FIG. 3 which comprises an equilateral triangle, the elongated polyhedric shape as illustrated in FIGS. 2 and 3 are first formed of suitable material such for example as foam urethane. The elongated polyhedric shape may have any desired length, it may for example be formed by a continuous extrusion process. The elongated shape as illustrated in FIGS. 2 and 3 is provided with three walls 1, 2 and 3 that are defined one from the other by the edges 4, 5 and 6. The elongated polyhedric shape is arranged with two of its edges, as for example, edges 5 and 6 parallel and in a common plane with the other edge 4 parallel and on one side of this common plane. For convenience the shape may be arranged on a flat surface such that the surface 3 is is on the flat surface. The polyhedric shape is then cut in a plane illustrated in FIG. 2 at 8. This cut may be effected by a knife or heated wire or any other suitable cutting means. The cut surface illustrated by the dotted line 8 lies in a plane perpendicular to the plane passing through edges 5 and in FIG. 2. This surface also lies at a 45 angle with respect to each of the edges 4, 5, and 6 as illustrated by the angles 8A in FIG. 2. After the cut is made the initial end segment 8C may be discarded. The polyhedric shape is then rotates [20 about its longitudinal axis so that the surface 3 moves into the plane formerly occupied by surface 1 and so that the edges 4 and 6 are now positioned in the same flat plane that edges 5 and 6 were in when described in connection with FIGS. 2 and 3. In this arrangement the edge 5 is now the edge that is one side of the common plane. Following the reorientation of the polyhedric shape a second cut is effected in a plane illustrated by the dotted line I in FIG. 5. The plane illustrated by the dotted line 10 is perpendicular to the plane passing through edges 4 and 6 and is at angle 10A of 45 with respect to edges 4, 5, and 6 or extensions thereof. When the polyhedric shape is cut in the plane 10 a tetrahedral shape 11 will drop or be served from the elongated polyhedric shape. This tetrahedral shape 11 may thereafter be used as a sponge. A second and subsequent tetrahedral shape is cut from the free end of the polyhedric shape by repeating the process. In the next subsequent step the polyhedric shape as illustrated in FIG. is rotated to a position as illustrated in FIG. 7 This is done by rotating the polyhedric shape in the same direction relative to FIG. 5 and FIG. 5 was rotated relative to FIG. 2. When the shape is thus rotated the surface formed by cutting the plane comprises the surface 12. A third cut is then effected in a plane illustrated by the dotted line 13. This cut is perpendicular to the surface I and is at an angle 13A of 45 with respect to edges 4, 5, and 6 as illustrated. By cutting along the plane defined by line I3, a second tetrahedral shape 14 is formed. Subsequent tetrahedral shapes may be formed by continuing the process. In this continual process the tetrahedral shape will be rotated intermittently 120 in the same direction and a cut will be effected at 45 relative to each of the side edges or their extensions.

The process described may obviously be used in an automated procedure in which an elongated polyhedric shape is continuously fed in a direction longitudinal of the shape under a cutting blade that is adapted to cut successfully at the same 45 angle as illustrated by the dotted lines 8, l0 and 13.

In following the process described above, two faces of each tetrahedral shape will be exposed prior to cutting on the elongated polyhedric shape. This will enhance possibilities of selective labeling or coating. Thus for example, the polyhedric shape may be readily coated on one surface with an abrasive material of one characteristic and on another surface with a second abrasive material of different characteristics. When cut the resulting tetrahedral shapes will be of three different kinds. One kind will have one surface only with one abrasive, a second kind will have one surface only with the second abrasive, and the third kind will have two surfaces each with one of the two abrasives. Other combinations such as labeling all three surfaces of the polyhedric shape are obviously possible. In such an arrangement each tetrahedral shape will have two labeled surfaces. In addition, other coatings and treatments may be efiected, for example, one surface may be coated with a soap material or both surfaces may be sealed to prevent transmission of water therethrough by a water impervious plastic laminate.

In an alternate embodiment of the method described in the present invention the starting material is a polyhedric shape having a rectangular and preferably a square cross section as illustrated in FIGS. 8 and 9.

The rectangular shape illustrated in FIG. 8 is oriented under a cutting edge for cutting in planes at a 45 angle with respect to all of the outer longitudinal surfaces 21, 22, 23 and 24 and their edges. This may be effected by orienting the elongated polyhedric shape beneath the cutting edge to a position with the cutting edge lying in a plane extending at an angle 29A of 45 with respect to each of the edges 25, 26, 27 and 28 as illustrated by the dotted line 29 in FIG. 9. In addition, the elongated polyhedric shape is oriented perpendicular to one plane passing through diagonally opposite edges 25, 27 and at an angle of 45 with respect to a plane passing through diagonal edges 26 and 28. Therefore, if a cutting edge is used that cuts parallel to a supporting surface spaced below the cutting edge, the polyhedric shape may, as illustrated be supported on one edge 28 on the supporting surface with edge 26 directly above edge 28 and immediately below the cutting edge so that when the blade cuts through the polyhedric shape the edge 26 is first cut and then the edges 25, 27 are simultaneously cut. In the process a first cut is made in a plane as illustrated by the dotted line 29 and a second cut is made in a plane, illustrated by dotted line 30, that is at an angle of with respect to the plane 29. These two cuts may be made successively or if desired, may be made simultaneously with a special X-shaped cutting element. Upon effecting the cuts in planes 29 and 30, twotetrahedral shapes l7 and 18 and an end segment 19 are formed. These tetrahedral shapes l7 and 18 may be used for purposes previously described and segment 19 may be discarded. In the next subsequent step the polyhedric shape, which now has an end view as illustrated in FIG. 10 with equilateral triangular faces 29 and 30 defined one from the other by the end edge 31, is rotated 90 to a position such as illus trated in FIGS. 11 and 12. In this subsequent position of rotational orientation the edge 25 is closest to the cutting blade and the edges 26 and 28 lie in a plane which is perpendicular to the planes in which the next subsequent cuts will be made. Subsequent cuts are then effected in planes illustrated by the dotted lines 35 and 36 of FIG. 11. These planes as illustrated in FIG. 11 are perpendicular to the plane of the paper and are perpendicular to each other. Further, they lie at 45 angles with respect to the edges 26 and 28 and intersect the angles formed respectively by edges 31, 28 and 31, 26. After these cuts in planes 35 and 36 three tetrahedral shapes are formed. These shapes 17A, 18A and [9A may be used as previously described.

The end view of the polyhedric shape illustrated in FIG. I] after removal of the tetrahedrons 17A, 18A and 19A is illustrated in FIG. 13. As illustrated the surfaces 35 and 36 formed by the previous cutting are exposed.

In the next subsequent step the polyhedric shape is rotated 90 from the position illustrated in FIG. 11 to the position illustrated in FIG. 15.

On reorientation of the polyhedric shape 90 edge 26 moves closest to the cutting blade and the edges 25 and 27 lie in a plane parallel to the cutting edge. A subsequent cutting process is then effected similar to the cutting process described in connection with FIG. 11 to effectively form three more polyhedric shapes. The process may then be continued in a similar manner as desired.

The method described in these embodiments may be practised by using a plurality of parallel spaced blades simultaneous cutting. After each group cutting of the polyhedric shape the shape is rotated to the appropriate angle as described and the group of blades are actuated once again to cut the shape while it is retained as an integral unit for this subsequent cut.

I claim:

I. A method of making a plurality of right angle tetrahedron shapes comprising forming an elongated polyhedric shape having a plurality of parallel edges extending lengthwise of said shape,

positioning said shape with two of its edges lying in a first plane and a third edge positioned parallel to and on one side of said first plane, cutting said shape in a plane normal to the first plane through each of said edges and at an angle of 45 to all of said edges, repositioning said shape after it is cut relative to said first plane to place one of said two edges and a third in said first plane and the other of said two edge on one side thereof and,

effecting a second cut through said shape in aplane normal to said first plane and at an angle of 45 to all of said edges whereby a tetrahedron shape is cut from said polyhedric shape.

2. A method as set forth in claim 1 including forming said polyhedric shape with three elongated walls and wherein said polyhedric shape is positioned prior to cutting by rotating it on its longitudinal axis over an arc of 120.

3. A method of making a plurality of shaped articles comprising forming an elongated polyhedric shape having a plurality of parallel edges extending lengthwise of said shape,

cutting said shape successively at spaced locations along the length of said shape in a series of parallel cutting movements and rotating said shape along its longitudinal axis intermediate said cutting movements, each of said rotations of said shape being effected through arcs of equal magnitude in which successive cutting movements cut said shape along nonparallel planes, each of said cutting movements being made at an angle which is nonperpendicular to the longitudinal axis of said elongated polyhedric shape whereby a plurality of said shaped articles are formed.

4. A method as set forth in claim 3 wherein said polyhedric shape has four walls with parallel edges. said cutting is effected at angles of 45 to said edges and said shape is rotated over an arc of 5. A method as set forth in claim 4 wherein a second cutting is effected in a plane at 90 to the plane of said first cutting with said planes intersecting at the axis of said polyhedric shape.

6. A method as set forth in claim 3 wherein said polyhedric shape has three walls with parallel edges, said cutting is effected at angles of 45 to said shape and said shape is rotated 

2. A method as set forth in claim 1 including forming said polyhedric shape with three elongated walls and wherein said polyhedric shape is positioned prior to cutting by rotating it on its longitudinal axis over an arc of 120*.
 3. A method of making a plurality of shaped articles comprising forming an elongated polyhedric shape having a plurality of parallel edges extending lengthwise of said shape, cutting said shape successively at spaced locations along the length of said shape in a series of parallel cutting movements and rotating said shape along its longitudinal axis intermediate said cutting movements, each of said rotations of said shape being effected through arcs of equal magnitude in which successive cutting movements cut said shape along nonparallel planes, each of said cutting movements being made at an angle which is nonperpendicular to the longitudinal axis of said elongated polyhedric shape whereby a plurality of said shaped articles are formed.
 4. A method as set forth in claim 3 wherein said polyhedric shape has four walls with parallel edges, said cutting is effected at angles of 45* to said edges and said shape is rotated over an arc of 90*.
 5. A method as set forth in claim 4 wherein a second cutting is effected in a plane at 90* to the plane of said first cutting with said planes intersecting at the axis of said polyhedric shape.
 6. A method as set forth in claim 3 wherein said polyhedric shape has three walls with parallel edges, said cutting is effected at angles of 45* to said shape and said shape is rotated 120*. 